Oxygen Concentration Curves
BSCC Physiology 014
Question:
Please draw the curve demonstrating the relationship between oxygen concentration and the partial pressure of Oxygen.
- Demonstrate how this changes in polycythaemic and anaemic individuals
- Explain what happens to a normal patient when 1/3 of the Haemoglobin is bound to carbon monoxide?
Examinee response
+ Show: Drawing and explanation in real-time video/audio
expand(document.getElementById('ddet1002587779'));expand(document.getElementById('ddetlink1002587779'))
Examiner explanation:
+ Show: Drawing and explanation in real-time video/audio
expand(document.getElementById('ddet636233393'));expand(document.getElementById('ddetlink636233393'))
+ Show Transcript
expand(document.getElementById('ddet1796978859'));expand(document.getElementById('ddetlink1796978859'))
Oxygen Concentration Curves
Oxygen is carried in the blood (in two ways): bound to Hb or dissolved
0.3 ml of oxygen is dissolved in every 100ml of blood
When bound to Hb
1 gm of HB binds 1.39ml O2
A patient with a normal range of Hb e.g. 15 (15g/100ml blood), the Hb will carry 20.8 ml O2 /100ml blood. (15 X 1.39=20.8)
Plotted on the Hb-O2 curve you can see 20ml of oxygen. Notice that at a PaO2 of 90mmhg the range is >95%.
A patient who is polycythaemic might have a Hb of 20. This Hb will carry 27.8 ml of O2/100ml of blood.
Note: that the concentration of oxygen per 100ml of blood is greater in the polycythaemic patient, but the partial pressure of oxygen and the HB O2 sa...
Source: Life in the Fast Lane - Category: Emergency Medicine Authors: Deanne Chiu Tags: Basic Science Physiology anaemia Oxygen Concentration Curve polycythaemia Source Type: blogs